Valve-gear



3 Sheets-Sheet, 1. K. KNOTT.

VALVE GEAR (No Model.)

Patetfited Mar. 13, 1888 new (No Model.) 3 Sheets-Sheet 2.

K.KNOTT.

, VALVE GEAR.

No. 379,400. Patented Mar. 13. 1888.

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3 SheetsSheet 3. K. KNOTT.

VALVE GEAR (No Model.)

Patented Mar. 13, 1888.

NITED STATES PATENT Fricn- KENNARD KNOTT, OF CHICAGO, ILLINOIS.

VALVE-GEAR.

SPECIFICATION forming part of Letters Patent No. 379,400, dated March13, 1888.

Application filed May 28, 1887. Serial No. 239,602. (No model.)

To all whom it may concern:

Be it known that I, KENNARD KNOTT, of Chicago, in the county of Cook andState of Illinois, have invented certain new and useful Improvements inSteam-Engines, of which the following is a description, reference beinghad to the accoinpanyingdrawings, forming a part of this specification,in which- Figure 1 is a plan view of a part of asteamengine having myimprovements applied thereto, the cylinder and steam-chest being shownin section. Fig. 2 is a plan view in detail showing the steam-chest insection, with a different valve and reversing mechanism, while theeccentric is represented in a changed position. Fig. 3 is a side view ofthe valveeccentric and the reversing device applied thereto. Fig. 4 is alike view showing the same in a reversed position; Fig. 5 is a sectionalview of said eccentric, taken upon the line a, Fig. 4. Fig. 6 is a sideview of the cocentric, showing the same in the act of being reversed.Fig. 7 is alike side view representing the collar as being partly brokenaway to show the means provided to allow the reversing-aim to pass thestud upon the valve-rod and to cause its engagement therewith upon areversal of the engine, and Fig. 8 is a side view in detail of thecollar attached to the engine-shaft to aid in reversing the eccentric.

Like letters of reference indicate like parts in the different figures.

One object of my invention is to provide a suitable reversing mechanismfor reversing the action of steamengines, whereby the usual link-motionmay be dispensed with, and a single eccentric may be employed to actuatethe valve.

A further object is to provide a movable valve-eccentric applicable toreversing engines and means for automatically adjusting the same uponthe reversal of the engine, so that the valve may occupy the properrelation in lead of the piston, whether the engine be run in onedirection or another, all of which I accomplish substantially in themanner hereinafter more particularly described, and delinitely pointedout in the claims.

In the drawings, A, Fig. 1, represents the I usual cylinder of asteam-engine. B is the piston; B, the piston-rod; B, the crank-rod, andB the crank upon the shaft Bfl journaled in the usual bearings. 0, Figs.1 and 2, is the steam-chest. In said figures respectively I have showndifferent ways of reversing the action of the engine. I will firstdescribe that shown in Fig. 1. Both are equally applicable to myimproved eccentric.

Within the steam-chest I secure by means of bolts 0 c, or in anywell-known way. a casting provided with double stean'i-portscommunicating through the ways D D with the usual steamways, E E, at therespective ends of the cylinder, and an exhaust-way, E" G. Located nearthe beginning of the ways D D are two-way cocks, F F, provided with armsF F, each of which is provided with studs or pinsff, arranged to engagewith slots f upon a plate, F which is rigidly attached to a rod, F,extending outwardly through the wall of the steamchest, whereby saidcocks, respectively, may be turned one-quarter of a revolution and inopposite directions.

G is a chamber or steamway communicating at one end with the steamway Dand at the other with the two-way cock F, when the latter is properlyadjusted therefor; and G is a chamber or way separated from the chamberG and passing beyond the same, as indicated in dotted lines, andcommunicating, respectively, with the cock F and steamway D.

G" is an exhaust-port separated from the others, as shown, andcommunicating with the usual exhaust-way, FF.

H is a slide-valve; H, the valve-rod. J is the valve-eccentric, and Jthe eccentric-rod, which is connected with the-usual shouldenj",attached rigidly to the eccentric-strap. The valves or cocks F F arerepresented as being so turned as to open the ways D D throughout theirentire length, and when the valve H is in the position shown in saidFig. 1 the steam enters the port D,as indicated by the arrow.theexhaust-steam escaping through the port Dand exhaust-port G Uponreversing the cooks F F the steam is directed into the chamber G.through which it is carried to the opposite end of the cylinder A, whilethe exhaust passes through the chambers or ways G G. An oppo sitemovement ofthe valve H reverses the conditions, closing the entrance tothe port D,when the steam is admitted through the ports D, G, and D andexhausted through the ways D, G, and G As the engine is operated so asto actuate the shaft in agiven direction,itis obvious that the eccentricshould occupy such a relation to the shaft as to reciprocate theslide-valve in lead of the piston; but upon reversing the engine it ismanifest that the conditions stated would be changed were the eccentricrigid with the shaft, and the valve would be so actuated as to produce agreat loss of steam, so much so as to render mostengines of this classof little practical value. Toovercome this objection I cause theeccentric J to be loosely attached to the shaft, but prevented fromlongitudinal movement thereon. Upon one side of the eccentric,and keyedrigidly to the shaft by means of a key, It, is a collar, K, providedwith projecting lugs K K. A Loose pin, J", is passed through theeccentric J and is sccured in place by means of a shoulder, j, and nutj,(better shown in Fig. 5,) by which itis free to revolve in its bearing.Formed upon or rigidly attached to said pin is an eccentric, L, which isloosely fitted between the lugs K K. If preferred, the pin may be rigidand the eccentric L may be attached to a loose sleeve thereon. Thevalve-eccentric J is preferably formed with a recess, J as shown inFigs. 3, 4:, and 5 therein, for the reception of said eccentric L andlugs K K.

Attached rigidly to the pin J is a pointed arm, M, which is extendedfrom the pin diametrically across the eccentric. L, the normal positionof which is such as to cause the arm M to lie in a plane at right anglesto the face of the lugs K whether its free end point in one direction orits opposite. Fig. 4 shows said eccentric L in its normal position,which it retains so long as the shaft revolves in the directionindicated by the arrow. Upon a reversal of the shaft the eccentric L islikewise.

reversed, so as to cause the arm M to pointin a reverse direction tothat shown in said fig ure, which reversal is accomplished as follows: Apin, J*, is rigidly attached, preferably, to the shoulder J of theeccentricrod, which is so adjusted as to engage with the extreme end ofthe arm M in whichever direction the shaft B is rotated.

Assuming the shaft to be rotated in one directionas, for example, thatindicated in Fig. 7this contact would either bend or break the arm Munless provision were made for one or the other to yield when brought incontact. To overcome this difficulty I preferably place a spring, J uponthe collar against which the eccentric L bears, said spring being soadjusted as to normally retain the eccentric L upon a end .of the arm Mto touch the pin J. said contact, as theshaft rotates in the directiondead-center, and at the same time to cause the Upon which produces ahalf-revolution of theeccentric L, leaving it in the position shown inFig. 4. This action shifts the position ofthe valveeccentric J, which,as stated, is loose upon the shaft, and retains it in such relation tosaid shaft as to give the proper lead to the valve. The relativepositions of the valve-eccentric are indicated by the full and dottedlines in Fig. 3. The eccentric L being normally upon a dead-center inwhichever dlrection the engine-sh aft is rotated, it is almost sure toretain the eccentric Jin its proper position. Should it change byaccident it is obvious that it could only remain so during a part of arevolution, as the arm M would readjust it upon the next revolution.

In lieu of the spring J the arm M may be made to spring or yieldsufficiently to permit it to slip by the pin J. The latter, ifpreferred, may be placed upon one of the lugsj or other part of theeccentric-strap, or upon a post, S, secured rigidly to the floor, as iuFg. 3, and the arm M adjusted accordingly 1n 1ts relation to theeccentric L. It is obvious that there may be two or more of said pins Jin the path traversed by the arm.

In Fig. 2 I have shown a different means for reversing the action of theengine, which consists, briefly, in providing duplicate sets ofsteam-ports, as N N and O O, communicatlng with the respective ends ofthe cylinder, exhaust-ports P P, and a sliding plate, Q, having openingsarranged to coincide with one or the other of said sets of ports,together with a double valve, H, arranged to operatein conjunctiontherewith. The sliding of said plate so as to close one and open theother set of ports serves to reverse the engine. I make no claim hereinto said construction, as the same is fully described in my applicationheretofore filed as Serial No. 213,977, September 20, 188 6.

In Fig. 1 the casting in the steam-chest 1 n which is formed the varioussteamways is shown as applied to an ordinary steam chest and cylinder ofthe usual pattern, with which it is detachably connected. It would beobvious to one skilled in the art that the same could be somewhatsimplified in details of construction if built with the engine.

I do not herein claim the reversing mechanism shown in Fig. 1, except incombination with the adjustable eccentric; but as the same may whenproperly manipulated be used with good results with a rigid eccentric, Ireserve the right herein to make a separate application for a patenttherefor.

Having thus described my invention, I claim- 1. Adevice forautomatically adjusting the valve -lead in steam engines, consisting ofa valveeccentric loosely mounted upon the engine-shaft, a smallereccentric loosely connected therewith and in turn with a rigid col larupon the crank-shaft, and provided with an arm extending from its axisand adjusted to engage upon its revolution with a rigid stud, wherebysaid small eccentric may be revolved and thus shift the valve-eccentricin its relation to the crankshaft upon the reversal of the engine ineither direction, substantially as described. 7

2. The combination, in a steam-engine, of a valve-eccentric looselymounted upon the shaft, a smaller eccentric in operative connectiontherewith, and with a rigid collar upon the crank-shaft and an armextending from its axis and adjusted to engage with a stud in the orbitof its revolution, whereby said smaller eccentric may be rotated uponthe reversal of the engine and normally retained upon its dead-center inwhichever direction the engine is propelled, substantially as described.

3. The combination, in a steam-engine, of a valve'eccentriclooselymounted upon the shaft, a smaller eccentric in operative connectiontherewith and with a rigid bearing arranged eccentrically to thecrank-shaft, an arm extending fro m the axis of said smaller shaft andadjusted to engage with a stud in the orbit of its revolution, and meansfor permitting said arm to yield during such engagement while the shaftis rotated continuously in one direction and to resume its normalposition when said stud is passed, substantially as and for the purposesspecified.

4E. The combination, with a steamengine and mechanism for reversing itsmovement, of the loose valve-eccentric J, rigid collar K, connected witheach other by means of the pin J and eccentric L, and means, as the armM and stud J, for revolving said eccentric L upon the reversal of theengine, substantially as and for the purposes described.

5. An automatic lead-adjusting mechanism for reversible steam-engines,consisting of a valve-eccentric loosely mounted upon the engine-shaft, asecondary eccentric adjusted to rotate between parallel lugs or facesextending laterally from a collar rigidly attached to the shaft and inturn connected by means of a pin with said valve-eccentric. and a fingerattached to said smaller eccentric and adjusted to engage with a studprojecting laterally from the eccentric-strap, said finger beingarranged in the plane of the greatest eccentricity of said smalleccentric, substantially as and for the purposes set forth.

6. The combination, with a steam-engine and means for reversing itsaction, of the loose valveeccentric J, a collar rigidly mounted upon theshaft and provided with lugs K K, an eccentric, L, loosely fittedbetween said lugs, pin J connected with said valve-eccentric, stud J",finger M. and means, as the spring J for permitting said arm to yieldupon engagement with the stud J* and to thereafter resume its normalposition. in which the dead center of the eccentric L is in a plane atright angles to the active faces of said lugs, substantially as and forthe purposes specified.

7. The combination, with a steam-engine, of a valve-eccentric looselymounted upon the engine-shaft, means, substantially as specified, forchanging its eccentricity with relation to a given radial line throughsaid shaft, double steainways arranged in the steam chest, a doubleslide-valve, and the two-way cocks F F, with means for rotating the samein opposite directions, substantially as and for the purposes described.

KENNARD KNOTT.

\Vitnesses:

D. H. FLETCHER, A. O. RAUSH.

